Problem 5 Saturated R-134a vapor enters a compressor at 10°F. At compressor exit, the specific entropy is the same as that at the inlet, and the pressure is 90 psia. Determine the R-134a exit temperature and the change in the enthalpy of R-134a. Problem 6 Refrigerant-134a at 280 kPa and 50°C undergoes an isothermal process in a closed system until its quality is 40 percent. On per unit mass basis, determine how much work and heat transfer are required.

Please choose the correct answer for each question: 1. Activity of a gas in equilibrium with solution is ______? A. its partial pressure; B.1.0;   C. its molar concentration;   D. 0.0 2. During a sorption procedure, the substance transferred from the gas or liquid phase to the solid phase is called ______ A. sorbent; B. sorbate;   C. partition;   D. none of the above 3. When a chemical has a lower KOW, it is more ______ A. hydrophobic; B. hydrophilic;   C. more absorbable;   D. less absorbable 4. _____ occurs on the adsorbent surface A. Adsorption; B. Sorption;   C. Absorption;   D. Adsorption and absorption 5. _____ addresses the change in the amount of a substance of interest with time. A. The equilibrium approach; B. The kinetic approach;   C. Henry’s Law;   D. Freudlich isotherm equation

What temperature is required to obtain 0.4%C at a distance of 0.3 mm beneath the surface of a 0.22% C steel in 2h, when 1.1% C is present at the surface? Assume that the iron is FCC. (Please see figure 5.12 below for diffusion coefficient data. Please use your notes for a table of erf() function values Diffusion coefficient D (cm²/s) ܐ ܐ ܐ ܐ 10- 10-5 10- 10-10 10-11 10-12 10-13 10-14 10-15 Temperature (°C) 2000 1500 1200 1000 900 800 700 600 Cin graphite Mg in MgO Ca in Cao H in FCC iron C in FCC iron Fe in FCC iron Fe in BCC iron H in BCC iron C in BCC iron Fe in FeO 500 5 6 7 8 9 10 11 12 13 104 T(K) Figure 5-12 The diffusion coefficient D as a function of reciprocal temperature for some metals and ceramics. In this Arrhenius plot, D represents the rate of the diffusion process. A steep slope denotes a high activation energy.

During a steady flow process, the pressure of the working substance drops from 200 to 20 psia, the speed increases from 200 to 800 ft/s the internal energy decreases 20 BTU/lb and the specific volume increases from 2 to 10 ft³/lb. No heat transferred. Determine the following: a)AKE in ft-lb;/Ibm b)APE in ft-lb/lbm c)AW: (flow work) ft-lb:/lbm d)AH in BTU e) Net work in hp for 15 lb/min of fluid (use mass flow rate for this item only)